[review v4] Fix unused function error

["Luis Machado (Code Review)" <gerrit@gnutoolchain-gerrit.osci.io>]

Luis Machado has posted comments on this change.

Change URL: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/753
......................................................................


Patch Set 4:

(1 comment)

| --- /dev/null
| +++ /COMMIT_MSG
| @@ -1,0 +1,30 @@ 
| +Parent:     1d61b032 (Remove more shifts for sign/zero extension)
| +Author:     Luis Machado <luis.machado@linaro.org>
| +AuthorDate: 2019-12-11 11:55:49 -0300
| +Commit:     Luis Machado <luis.machado@linaro.org>
| +CommitDate: 2019-12-11 14:06:52 -0300
| +
| +Fix unused function error
| +
| +Attempting to build GDB in Ubuntu 16.04.6 LTS on x86_64, I ran into warnings
| +that caused the build to fail:
| +
| +binutils-gdb/gdb/gdbsupport/safe-strerror.c:44:1: error: ‘char* select_strerror_r(char*, char*)’ defined but not used [-Werror=unused-function]  select_strerror_r (char *res, char *)
| +
| +The diagnostics macros seem to expand correctly to their respective pragmas,
| +but it doesn't seem to have an effect on the warning. I tried to use the
| +pragmas explicitly and got the same result.
| +
| +ATTRIBUTE_UNUSED works fine in this case, if you put it in both functions,
| +which should fix warnings for both gdb and gdbserver builds.
| +
| +The compiler version is gcc (Ubuntu 5.4.0-6ubuntu1~16.04.11) 5.4.0 20160609.

PS3, Line 21:

I tried #1 with "-Wunused" and it doesn't work.

I'm trying to find some more information on when exactly this ceased
to be a problem (if at all). I take it this was fixed, since Christian
didn't see this problem, neither did the buildbot after the first fix.

The warnings in include/diagnostics.h tell us to use these macros
guarded by known versions, like so:

#if __GNUC__ >= 10
#  pragma GCC diagnostic push
#  pragma GCC diagnostic ignored "-Wformat-diag"
#endif

We could have a construct like the above, guarded for known-to-work
compiler versions, and use ATTRIBUTE_UNUSED for the rest.

| +
| +gdb/ChangeLog:
| +
| +2019-12-11  Luis Machado  <luis.machado@linaro.org>
| +
| +	* gdb/gdbsupport/safe-strerror.c: Remove diagnostics.h
| +	(select_strerror_r): Use ATTRIBUTE_UNUSED instead of the diagnostics
| +	macros.
| +

-- 
Gerrit-Project: binutils-gdb
Gerrit-Branch: master
Gerrit-Change-Id: Iad6123d61d76d111e3ef8d24aa8c60112304c749
Gerrit-Change-Number: 753
Gerrit-PatchSet: 4
Gerrit-Owner: Luis Machado <luis.machado@linaro.org>
Gerrit-Reviewer: Luis Machado <luis.machado@linaro.org>
Gerrit-CC: Christian Biesinger <cbiesinger@google.com>
Gerrit-CC: Pedro Alves <palves@redhat.com>
Gerrit-Comment-Date: Wed, 11 Dec 2019 17:58:33 +0000
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Comment-In-Reply-To: Pedro Alves <palves@redhat.com>
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